1. Field of the Invention
A system and method consistent with the present invention relates to a wireless local area network system, and more particularly, to a wireless local area network system and an operation method therefor in which the system has access points (APs) capable of supporting host mobility.
2. Description of the Related Art
With the fast spread of wireless communications and the growth of the Internet, Internet services in wireless environments have been increasingly demanded and, accordingly, users want to use the Internet through wireless communication services by which mobility can be guaranteed. Wireless communication technologies such as wireless LAN, mobile IP, MANET, and so on, have given rise to recent active research and development.
Of the communication networks, the wireless local area network (WLAN) has an advantage of supporting services of a certain standard, but also has a disadvantage in that its use is limited to a certain range.
A general wireless IPv6 host without a mobile IPv6 stack has a problem of poor continuity of services occurring when the host moves to an access point (AP) for a different router.
FIG. 1 is a view for schematically showing a conventional general wireless local area network system.
A wireless local area network 100, which may be a network in a corporation or a network in a campus, has a gateway 10 connected to the Internet 200 which is an external network, the gateway 10 has plural access routers (ARs) 20 and 30 connected thereto, for example, and one access router AR1 20 has plural access points (APs) 21, 22, . . . , and 31 connected thereto, each of which deals with mobile hosts (MH) within a certain range thereof. In here, the mobile hosts under the access router AR1 20 are assigned IP addresses based on prefix information (Prefix:A) of the access router AR1.
However, such a conventional wireless local area network has the following limits to the mobility support for the mobile hosts.
For example, if a mobile host (MH) associated with an AP AP1_1 21 connected to the first access router AR1 20 moves into a range dealt with by an access point AP1_2 22 connected to the first access router AR1 20, the mobile host (NH) is supported by the access point AP1_2 22. That is, the access points AP1_1 21 and AP1_2 22 connected to the first access router AR1 20 can communicate with each other through the Inter Access Point Protocol (IAPP). Accordingly, if the mobile host (MH) communicating with the Internet 200 by using the access point AP1_1 21 moves into a range covered by the access point AP1_2 22, the mobile host (MH) can be continuously provided with current services through the IAPP.
However, if the mobile host (MH) moves into a range of an access point AP2 31 connected to a second access router AR2 30, the mobile host (MH) is assigned a new Internet Protocol (IP) address by the access point AP2 and, at this time, prefix information of the IP address is based on prefix information (Prefix:B) of the second access router AR2 30.
Accordingly, the mobile host (MH) is recognized as a new network and undergoes a new association process, so it cannot continuously receive current services.